Kettle furnace



March 6, 1951 Filed Jan. 20. 1950 0. R. OLSON 2,543,982

' KKETTLE FURNACE 2 Sheets-Sheet 1 z I w;

INVENTOR. Chm/"Q0600.

Patented Mar. 6, 1951 UNITED STATES PATENT OFFICE KE'ITLE FURNACE Oscar R. Olson, Pittsburgh, Pa.

ApplicationJanuary 20, 1osogserial Nurses?1 (olezcs li) '3Claims. I This invention relates generally to improvementsin kettle furnaces and moreparticularlyto kettle furnaces'heated by slowburning fuels.

Kettlefurnaces are provided with a lair'getank containing a liquid bath such as Houghton. salt solution, lead, tin or zinc for-heating or coatin metals by vimmersiontl'lerein. Kettle furnaces heretoforehave been constructed to utilize a fast burning fuel such as 'naturalgas, gasoline, orla very light oil quickly transformed intoa gas and discharged from a-series of burnerslp'laced closely adjacent one another along the sides of the tank. These highly volatile fuelsare, directed into a bed of ceramic particles that glow and maintain very fast and continuous combustion. Such astructure is disclosedinmy kettle furnace patent, -No.- 2,460 ,392, of February 1, 1949.

Such-a structurecould not utilize a slow =burning fuel-such-as powdered coal, tar, fue1-oils or slow burning gases that produce luminous-flames. These fuels are more economical than thehighly volatile fuels. The heavier liquid fuels require preheating but they provide a constant uniform heat when properly prepared and controlled. In order to utilize these qualities of slow burning fuels an entirely diiferent method and kettle furnace structure is necessary. The same gen- .eral character of furnace foundation and flue may be employed but the combustionchamberis required to be large and preferably elongated in which toconfine the iburningiuel. Such an enclosed combustion chamber must be provided with regulated ports that control th fiow of the burning fuel from the combustion chamber to the secondary combustion chamber where combustion is completed and the gases flow through the .downtake where it heats the tank and is dischargedthrough graduated openings to the flues. The ports from the combustion chamber are best .graduated as well as-regulated by valves to conefficient heat transfer is made to. the tank. The

graduated size of the ports, together with their valved control, permits the uniform distribution of heat along the kettle. It prevents the fuel from being discharged prematurely which would result in combustion being carried on in the downtakeand flue.

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.To-obtain these objects and advantages it is preferable'to construct a bridge wall between the furnace side walls and the tank. These bridge walls extend 'the'full length of the furnace being connected to the end walls. Upper and lower slabs supported between the bridge wall and the furnace sidewalls divide the space into a long due at the bottom and a long'combustion chamber thereabove. The top slab forms the top of the combustion "chamber and provides a suitable surface on which to support the valves regulating the, ports from the combustion chamber to thesecondary chamber, thence to the downtake. These valves extendthrough the furnace side wall to "be readily adjusted for the character offuelselected to fire'th'e furnace.

Other objects and advantages appear in the followingdescription and'claims.

The accompanying'drawing shows, for the purpose of 'exemplification without limiting the invention or claims thereto, certain practical embodiments of th invention wherein:

Fig. 'l isa top viewof the kettle furnace showing part in plan and part in section on the line I-l of Figl3;

I Fig. '2 is a vertical sectional view taken on the -li"ne'2--2 of Fig. 1 and Fig. 3 is an end view of the kettle furnace, -partly in vertical section and partly in elevation on the line 3-3of'Fig. 1.

Referring to the drawings the furnace is built within the "pit defined by the walls I which is lined. with reinforced concrete and is provided with a foundation as indicated at '2. The pit l forms 'a moat 3 that extends along both sides of the furnace and is connected at least one end thereof. As shown in Fig. 3, the furnace mat 4 is constructed on the foundation 2 and is ar ranged to support. the furnace and the furnace walls. A plurality of buc'kstays 5 are embedded upright in'the foundation land are employed 'to support the side walls 9 and 9 and end walls [1 and I8 of the furnace. Adjacent each of the buckstays and. at other selected positions the moat 3 is provided with a plurality of partitions 5 having weirop'enings'l in the upper portion thereof. The moats 3 are prepared to receive the contents of. the kettle if the latter becomes ruptured during/operation in order to. save the furnac'e tile structure. The moat 3 is lower than any other p'ortion o'fthe furnace including the flues and prevents the contents of the kettle from stopping up the dues. The partition walls 6 and the side walls of the moat 3 are provided with a batter for the purpose of readily removing the solidified material in the moat. A chain, such as indicated at 8 in Fig. 3, may be suspended from the wall into the compartments formed by the partition 5 for the purpose of moving solidified materials such as lead or zinc.

The kettle or tank H1 is ordinarily constructed of heavy steel plate and is rectangular in shape. This tank is seated upon the mat t supported on the foundation and a small retaining wall ll extends therearound for the purpose of properly anchoring the tank in position. A series of piers I2 extend from the wall I I to more than half way up the side wall of the tank for the purpose of supporting the same in the position of the buckthe bottom of the tank the furnace is provided with a flue on each side thereof as indicated at l5 and I6. These flues extend the full length of the furnace starting from the end wall if and extending through the end wall is where they are connected to a lateral flue l9 that runs to the stack indicated at 20.

As shown in Figs. 2 and 3, each flue is provided with a series of lateral openings 2| that extend from the bottom of the flue to the moat 3 and which are closed by the flap Valves 22 for L the discharge of the heated liquid to the moat if the tank ruptures. On the opposite side of the flue the vertical bridge wall 23 separates the flue from the tank and provides the downtake passages 24 between the piers I2. Part way up the bridge wall 23 is a series of slabs 25 that form the top of the flues and the bottom of the primary combustion chambers 26. The combustion chambers are closed at the top by the slabs 21 that form the bottom of the secondary combustion chamber 28 which opens to the downtake passages 24.

The combustion chambers 26 may extend the full length of the furnace. However, itis deemed preferable to divide them in two thus providing four combustion chambers, two on each side of the furnace. These four combustion chambers are made by the transverse partition walls 30 as shown on Fig. 2. Each of the elongated combustion chambers 26 is supplied with fuel from the burners 3| disposed in the end walls of the combustion chamber. The combustion chamber is completely closed to the rest of the furnace except through the graduated series of ports 32 in the combustion chamber roof slabs 2?. ports 32 are graduated in size, being larger adjacent the burner and smaller adjacent the other end of the combustion chamber. Thus, when two combustion chambers are formed on one side of the furnace there are two sets of graduated ports 32, the largest port being adjacent the burners and the next and other ports being consecutively smaller in size toward the center of the furnace. Not only are these ports graduated in accordance to the size of their opening, but they are also controlled by the slide valve 33 which may be slid over the slabs Z! to regulate the extent of each port opening. The slide valves extend through the furnace wall as indicated in Fig. 1 so that they may be adjusted, thereby control- It will be noted that the The ling the amount of fuel passing from the combustion chamber through each of the ports.

Thus, by providing elongated combustion chambers, one is able to employ a slow burning fuel such as powdered coal, tar, oil or a luminous gas and control the combustion thereof within the combustion chambers 26, permitting only that portion of the fuel that is prepared for complete combustion, to discharge through the ports 32 so that it may freely burn in the secondary combustion chamber 28 and be discharged through the downtakes 24 to supply heat to the tank 10. The downtakes 24 have a series of openings through the bridge wall 23 as indicated at 34. These are flue openings that connect the downtake with the flue. These openings are preferably graduated from one end of the fines to the other. Owin to the fact that the stack 20 is adjacent one end of the flues, it is necessary to place the smallest of the flue openings 34 adjacent the stack end of the flue or a short circuiting draft would result from the secondary combustion chamber 28 to the flue. Thus, the openings 34 are graduated from the left to the right as shown in Fig. 2 which is a feature of my previously mentioned patent.

A bay 35 is formed in the right end of the tank as shown in Figs. 1, 2 and 3. The secondary combustion chamber 28 is provided with a covered burner inspection hole 36 at either end of the secondary combustion chambers 28 to permit inspection of the flame passin from the ports 32 to the downtakes 24.

Thus, by providing a relatively long and confined combustion chamber, one is enabled to discharge the slow burning fuel therein and control its combustion within the primary combustion chamber and the escape of the burning fuels and prepared fuel for combustion in the second ary combustion chamber may be determined at the proper time to effect the greatest heat transfer to the open kettle tank. The ports from the primary to the secondary combustion chamber are more readily controlled by the valves 33 if they are graduated in size as shown, thereby preventing a short circuit from the primary to the secondary combustion chamber. The greatest pressure of combustion is remote of the burner and it is therefore necessary to provide the larger ports 32 connecting the primary to the secondary combustion chamber closely adjacent the burner.

I claim:

1. A kettle furnace comprising a foundation, an open top tank sup-ported on the foundation, furnace end walls supported on the foundation and extending laterally beyond both sides of the tank, furnace side walls supported on the foundation and connecting the end walls but spaced from the sides of said tank, a roof closing between the walls and the rim of said tank, a bridge wall on each side of said tank spaced from the roof and connecting the end walls to longitudinally divide the space between the furnace side walls and the tank to form a connected secondary combustion chamber and a downtake adjacent the tank, upper and lower slabs connectin each bridge wall and the adjacent furnace side wall to form a primary combustion chamber under the secondary combustion chamber and a flue therebelow, a stack connected to one end of each flue, a burner connected to one end of each primary combustion chamber for discharging a slow burning fuel therein, a series of graduated openings through each bridge wall from each flue to its respective downtakes which openings are smaller in size adjacent the stack end of said flue, and a series of graduated ports from each primary combustion chamber to its respective secondary combustion chamber which ports are larger in size adjacent the burner.

2. A kettle furnace comprising a foundation, an open top tank supported on the foundation, furnace end walls supported on the foundation and extending laterally beyond both sides of the tank, furnace side walls supported on the foundation and connecting the end walls but spaced from the sides of said tank, a roof closing between the walls and the rim of said tank, a bridge wall on each side of said tank spaced from the roof and connecting the end walls to longitudinally divide the space between the furnace side walls and the tank to form a connected secondary combustion chamber and a downtake adjacent the tank, upper and lower slabs connecting each bridge Wall and the adjacent furnace side wall to form a primary combustion chamber under the secondary combustion chamber and a flue therebelow, a stack connected to one end of each flue, a burner connected to one end of each primary combustion chamber for discharging a slow burning fuel therein, a series of graduated openings through each bridge wall from each flue to its respective downtakes which openings are smaller in size adjacent the stack end of said flue, a series of graduated ports from each primary combustion chamber to its respective secondary combustion chamber which ports are larger in size adjacent the burner, and valve means regulating the extent of opening of said graduated ports.

3. A kettle furnace comprising a foundation, an open top tank supported on the foundation,

furnace end walls supported on the foundation and extending laterally beyond both sides of the tank, furnace side walls supported on the foundation and connecting the end walls but spaced from the sides of said tank, a roof closing between the walls and the rim of said tank, a bridge wall on each side of said tank spaced from the roof and connecting the end walls to longitudinally divide the space between the furnace side walls and the tank to form a connected secondary combustion chamber and a downtake adjacent the tank, upper and lower slabs connecting each bridge wall and the adjacent furnace side wall to form a primary long combustion chamber under the secondary combustion chamber and a long flue therebelow, a stack connected to one end of each long flue, a lateral bafiie wall dividing each long primary combustion chamber into two short primary combustion chambers, a burner connected to one end of each short primary combustion chamber for discharging a slow burning fuel therein, a series of openings through each bridge wall from each flue to its respective downtakes, and a series of regulatable valved ports from each short primary combustion chamber to its respective secondary combustion chamber.

OSCAR R. OLSON.

, REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 798,723 Casaday Sept. 5, 1905 1,522,914 Schumacher Jan. 13, 1925 2.460.392 Olson Feb. 1, 1949 

